You can earn all the way up to 1.2.
Good standing (not banned in the past) yields you with +0.5
You only need 5,000 achievement points from unique achievements across all your characters on all expansions to get +0.7 which means you're earning the highest possible amount of points daily, (12 before squish, 1.2 after).
If you happen to get banned at any point, you instantly forfeit the +0.5, meaning you need 8,000 achievement points to get 1 point per day, you can never reach 1.2 per day.
points > 8000 = +1
points > 7000 = +0.9
points > 6000 = +0.8
points > 5000 = +0.7
points > 4000 = +0.6
points > 3000 = +0.5
points > 2000 = +0.4
points > 1000 or 1000 = +0.3
points < 1000 = 0 total, good standing is not factored in here either, meaning you have to atleast play the game to begin gaining points.